Re: Viewsonic 17 power issue

OK, I pulled the HOT heat sink with devices.


A 2SC4288A, I assume is the HOT, is shorted all the way around.

An IRFPF40, which may not be a transistor, is short on what would
normally be base to collector. Open emitter to base. It is an
International Rectifier device (hence IR...).

I know there are components like caps that can blow these out -
anybody have a familiarity with this one?


The unit was working at home with the computer at the resolution that
I have run forever. So it isn't an incompatible issue. The monitor
will also take just ablut anything the adapter can give it.




On Tue, 16 Sep 2008 00:10:19 GMT, bill@xxxxxxxxxx wrote:

I have a Viewsonic 17, model 1782, Chassis series 17HV2, computer
monitor - made by Matsushita 1994.
Was working fine - cut it off, transported to office - carefully!
Turned on - power LED came on for about 1 sec then faded off.
When it goes off, there is a sound like the degaussing coil
energizing. I pulled that connection and it does the same thing.

Seems like there is a load on one of the rails causing the whole
switcher to shut down. All caps (that I can see without removing the
main PCB) look OK - no buldging. Nothing smoking, smelling, or
burning.

I have a schematic for a 17G but I can't find the power LED on it.
Some connector designations match - like the degaussing coil
connector. So it is probably not exactly a 1782.

Any experience or how to troubleshoot hints??

thanks

bill
.

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